Pixel circuit and driving method

Abstract

The present application provides a pixel circuit and a driving method. Writing of a data signal to each sub-pixel circuit is independently controlled by a respectively corresponding demultiplexing signal, which is beneficial to realize an ultra-high frequency driven display. The first sub-pixel circuit and the second sub-pixel circuit share the same data signal, so that less data lines are required. The driving transistor is a polysilicon thin-film transistor, and the compensation transistor is an oxide thin-film transistor, so a current leakage of the driving transistor is reduced or eliminated.

What is claimed is: 
     
         1 . A pixel circuit, comprising:
 a first sub-pixel circuit;   a second sub-pixel circuit; and   a writing circuit connected to the first sub-pixel circuit and the second sub-pixel circuit, wherein the writing circuit is configured to control a data signal to be coupled to the first sub-pixel circuit based on a first demultiplexing signal, and control the data signal to be coupled to the second sub-pixel circuit according to a second demultiplexing signal.   
     
     
         2 . The pixel circuit according to  claim 1 , wherein an input signal of the first sub-pixel circuit is the same as an input signal of the second sub-pixel circuit;
 wherein the input signal comprises at least one of a first power signal, a second power signal, a light-emitting control signal, a scan signal, and an initial voltage signal.   
     
     
         3 . The pixel circuit according to  claim 1 , wherein the writing circuit comprises:
 a first thin-film transistor coupled to the first sub-pixel circuit and configured to control the data signal to be coupled to the first sub-pixel circuit according to the first demultiplexing signal; and   a second thin-film transistor coupled to the second sub-pixel circuit and configured to control the data signal to be coupled to the second sub-pixel circuit according to the second demultiplexing signal;   wherein the first demultiplexing signal is different from the second demultiplexing signal.   
     
     
         4 . The pixel circuit according to  claim 1 , wherein the first sub-pixel circuit or the second sub-pixel circuit comprises:
 a driving unit connected in series to a light-emitting circuit consisting of a first power signal and a second power signal and configured to control a current flowing through the light-emitting circuit; and   a compensation unit coupled to the driving unit and configured to adjust a potential of a control terminal of the driving unit to a potential of an output terminal of the driving unit according to a second scan signal, so as to reduce or eliminate a current leakage of the driving unit.   
     
     
         5 . The pixel circuit according to  claim 4 , wherein the first sub-pixel circuit or the second sub-pixel circuit further comprises:
 an initialization unit connected to the driving unit and configured to control an initial voltage signal to be coupled to the driving unit according to the first scan signal.   
     
     
         6 . The pixel circuit according to  claim 5 , wherein the first sub-pixel circuit or the second sub-pixel circuit further comprises:
 a storage unit coupled to the driving unit, the initialization unit, and the first power signal, wherein the storage unit is configured to adjust the potential of the control terminal of the driving unit.   
     
     
         7 . The pixel circuit according to  claim 6 , wherein the first sub-pixel circuit or the second sub-pixel circuit further comprises:
 a light-emitting unit connected in series to the light-emitting circuit; and   a light-emitting control unit connected in series to the light-emitting circuit and configured to on-off control the light-emitting unit to emit light according to a light-emitting control signal.   
     
     
         8 . The pixel circuit according to  claim 7 , wherein the first sub-pixel circuit or the second sub-pixel circuit further comprises:
 a reset unit connected to the initial voltage signal and an anode of the light-emitting unit and configured to control the initial voltage signal to be coupled to the anode of the light-emitting unit according to a third scan signal to reset a potential of the anode.   
     
     
         9 . A pixel circuit, comprising:
 a first sub-pixel circuit; and   a writing circuit connected to the first sub-pixel circuit and configured to control a data signal to be coupled to the first sub-pixel circuit according to a first demultiplexing signal.   
     
     
         10 . The pixel circuit according to  claim 9 , wherein the first sub-pixel circuit comprises:
 a driving transistor, wherein a source of the driving transistor is connected to an output terminal of the writing circuit; and   a compensation transistor, wherein an input terminal of the compensation transistor is connected to a gate of the driving transistor, an output terminal of the compensation transistor is connected to a drain of the driving transistor, and a control terminal of the compensation transistor is connected to a second scan signal and configured to adjust a potential difference between the gate and the drain of the driving transistor according to the second scan signal to reduce or eliminate a current leakage of the driving transistor.   
     
     
         11 . The pixel circuit according to  claim 10 , wherein the driving transistor is a polysilicon thin-film transistor, and the compensation transistor is an oxide thin-film transistor. 
     
     
         12 . The pixel circuit according to  claim 11 , wherein the first sub-pixel circuit further comprises an initialization transistor;
 an input terminal of the initialization transistor is connected to an initial voltage signal, a control terminal of the initialization transistor is connected to a first scan signal, and an output terminal of the initialization transistor is connected to the gate of the driving transistor.   
     
     
         13 . The pixel circuit according to  claim 12 , wherein the first sub-pixel circuit further comprises a storage capacitor;
 a first end of the storage capacitor is connected to a first power signal, and a second end of the storage capacitor is connected to the gate of the driving transistor.   
     
     
         14 . The pixel circuit according to  claim 13 , wherein the first sub-pixel circuit further comprises a first light-emitting control transistor, a second light-emitting control transistor, and a light-emitting device;
 an input terminal of the first light-emitting control transistor is connected to the first power signal, and an output terminal of the first light-emitting control transistor is connected to the source of the driving transistor;   an input terminal of the second light-emitting control transistor is connected to the drain of the driving transistor, and the light-emitting control signal is connected to a control terminal of the first light-emitting control transistor and a control terminal of the second light-emitting control transistor; and   an anode of the light-emitting device is connected to an output terminal of the second light-emitting control transistor, and a cathode of the light-emitting device is connected to a second power signal.   
     
     
         15 . The pixel circuit according to  claim 14 , wherein the first sub-pixel circuit further comprises a reset transistor;
 an input terminal of the reset transistor is connected to the initial voltage signal; a control terminal of the reset transistor is connected to a third scan signal; and an output terminal of the reset transistor is connected to the output terminal of the second light-emitting control transistor.   
     
     
         16 . The pixel circuit according to  claim 12 , wherein the initialization transistor is an oxide thin-film transistor. 
     
     
         17 . A driving method of a pixel circuit, wherein the pixel circuit is provided with a first sub-pixel circuit, a second sub-pixel circuit, and a writing circuit, and the driving method comprises:
 providing a first demultiplexing signal, a second demultiplexing signal, a data signal, and a corresponding input signal, wherein the input signal comprises at least one of a first power signal, a second power signal, a light-emitting control signal, a first scan signal, a second scan signal, a third scan signal, and an initial voltage signal;   the writing circuit controlling the data signal to be coupled to the first sub-pixel circuit according to the first demultiplexing signal;   the writing circuit controlling the data signal to be coupled to the second sub-pixel circuit according to the second demultiplexing signal;   the first sub-pixel circuit driving a first light-emitting unit according to the input signal to perform a first display operation; and   the second sub-pixel circuit driving a second light-emitting unit according to the input signal to perform a second display operation;   wherein a frequency of the third scan signal is less than or equal to a sum of frequencies of the first demultiplexing signal and the second demultiplexing signal.   
     
     
         18 . The driving method according to  claim 17 , wherein the writing circuit comprises a first writing circuit and a second writing circuit;
 the first writing circuit controls the data signal to be coupled to the first sub-pixel circuit according to the first demultiplexing signal; and   the second writing circuit controls the data signal to be coupled to the second sub-pixel circuit according to the second demultiplexing signal.   
     
     
         19 . The driving method according to  claim 18 , wherein a frequency of the first demultiplexing signal is the same as a frequency of the second demultiplexing signal. 
     
     
         20 . The driving method according to  claim 17 , wherein the first demultiplexing signal and the second demultiplexing signal work at different times.